<p>When developing a web project, a very curious question arises sometimes: what
could the maximum possible performance be? Or, in other words, how many
concurrent visitors can the current configuration serve until the delay becomes
unacceptably apparent?</p>

<p>For example: a web project was properly optimized for high loads and hosted
on a high performance server. Conventional tests showed acceptable results for
emulated 3.000.000 daily hits: the average page generation time of 0.5 sec, the
average web page transmission time of 1 sec. However, what the limit can
be? </p>

<p>This test may show that, for example, the maximum possible performance is
5.500.000 daily hits with the average page generation time of 1 sec and the
average web page transmission time of 3 sec. It is quite obvious that such
values ensure the system has almost two-fold redundancy and will hold.</p>


<p>Open "Settings > Performance > Performance Panel > Scalability" and run the
stress test using the following initial values:</p>

<ul>
<li>Initial Concurrent Connections: 1</li>
<li>Final Concurrent Connections: 5</li> 
<li>Increment Concurrent Connections By: 1</li> 
<li>Maximum Test Duration: 5 minutes</li>
<li>Page: the main or index page (e.g. /index.php). You can specify any other
  popular page.</li> 
 </ul>

<p>The page generation time should not exceed 0.5 sec. and should not be
increasing too fast with the growing concurrent connections. No errors must
occur. The minimum number of pages per second should match the expected daily
hits divided by 86400. The page acquisition time should not exceed 1 sec.</p>